This paper first reviews the origin and development of green infrastructure (GI) and then summarizes the context,formation and development from the perspectives of human settlements,ecological protection,and green technology.Then,it describes GI from spatial,functional,and elemental aspects.The relationship of GI with ecological services is also elucidated.Through a literature review,the international research frontiers of GI are assessed for the following topics:climate change,human health,air quality,stormwater management,public awareness,community participation,and evaluation research.Finally,this paper predicts future developments in GI based on the current status of GI research and problems in China.